Clean water through living systems

Soil, plants, and biology treat water more effectively than chemicals — and create habitat, food, and resilience at the same time.

Natural water treatment uses the same biological processes that have cleaned water in forests, wetlands, and floodplains for millennia. Constructed wetlands, bioswales, and living soil filters harness the power of plant root zones, beneficial microorganisms, and layered soil media to break down contaminants, filter particulates, and polish water to a standard that often exceeds conventional treatment — all without chemical inputs or energy-intensive equipment.

These systems are not theoretical. Constructed wetlands treat municipal wastewater across Europe and North America. Bioswales manage stormwater in cities from Portland to Copenhagen. On rural properties and homesteads in BC, the same principles apply at a smaller scale: greywater from your house can irrigate your orchard through a mulch basin, farm runoff can pass through a planted swale before reaching a pond, and a series of treatment cells can turn a liability into a productive, habitat-rich water feature. The result is cleaner water, healthier soil, and a more resilient property.

System types

Constructed Wetland / Reed Bed

A horizontal subsurface flow wetland with gravel media and wetland plants. Wastewater flows horizontally through a gravel bed planted with native wetland species, where root-zone bacteria break down organic matter, nitrogen, and pathogens. Water never surfaces — it stays below the gravel, eliminating odour and insect issues.

Best for

  • Greywater treatment and reuse
  • Septic effluent polishing
  • Farm runoff treatment

How it works

Wastewater enters at one end and flows horizontally through a gravel root zone. Aerobic and anaerobic bacteria in the root zone decompose organic matter. Plants take up nutrients (nitrogen, phosphorus) and transpire water. Treated water exits at the far end via a level-controlled outlet.

Sizing

  • Greywater: 5 m² per person
  • Septic effluent polishing: 10 m² per person

Plants (BC native)

  • Bulrush (Schoenoplectus)
  • Cattail (Typha latifolia)
  • Common reed (Phragmites australis)
  • Sedge (Carex spp.)

Maintenance

Minimal. Annual plant thinning and occasional gravel bed inspection. No chemical inputs. No moving parts.

BC Regulatory Note: Treating sewage or septic effluent requires a sewage disposal permit under the BC Sewerage System Regulation. Greywater systems may also require health authority approval depending on your regional district. Contact your local health authority or FrontCounter BC before construction.

Living Soil Filter / Mulch Basin

Greywater is distributed via a branched drain network to mulch-filled basins planted with fruit trees or berry shrubs. The mulch and soil biology break down soaps and organic matter while tree roots take up the water and nutrients. Based on the work of Art Ludwig and Brad Lancaster.

Best for

  • Kitchen sink greywater
  • Shower and bath water
  • Laundry water
  • NOT toilet water (blackwater)

How it works

A branched drain (no pump) splits greywater flow evenly between mulch basins. Each basin is a shallow pit filled with wood chip mulch, planted with a productive tree or shrub. Biology in the mulch layer breaks down surfactants and organic matter. Tree roots take up water and nutrients. No standing water, no odour.

Sizing

  • 1 basin (1m x 1m x 300mm deep) per 50 L/day of greywater
  • Typical household: 3-6 basins

Plants

  • Apple, pear, plum (fruit trees)
  • Blueberry, raspberry, currant (berry shrubs)
  • Any water-loving productive plant

Maintenance

Top up mulch annually. Avoid boron-based soaps and bleach. Use plant-friendly cleaning products.

BC Regulatory Note: Greywater diversion systems are not explicitly regulated province-wide, but some regional health authorities require notification or approval. Check with your local health authority before installing. Do not connect toilets or kitchen food waste disposers.

Bioswale / Vegetated Filter Strip

A planted swale designed specifically to treat surface runoff. Unlike a standard swale (which focuses on infiltration), a bioswale is engineered with specific plant communities and check dams to slow water, trap sediment, and break down pollutants through biological activity in the root zone.

Best for

  • Driveway and road runoff
  • Parking area drainage
  • Agricultural field edge treatment
  • Roof runoff pre-treatment

How it works

Surface runoff enters the swale and is slowed by dense plantings and check dams. Sediment settles out. Plants and root-zone microbes filter dissolved pollutants (hydrocarbons, nutrients, metals). Treated water infiltrates or exits via a controlled outlet.

Sizing

  • Swale length (m) = contributing area (m²) x 0.05
  • Minimum length: 10 m
  • Typical width: 0.6 - 1.5 m
  • Typical depth: 0.3 - 0.6 m

Plants (BC native)

  • Slough sedge (Carex obnupta)
  • Soft rush (Juncus effusus)
  • Willow (Salix spp.)
  • Red osier dogwood (Cornus stolonifera)

Maintenance

Remove accumulated sediment annually. Replant bare patches. Clear inlet and outlet structures after storms.

BC Regulatory Note: Bioswales treating surface stormwater typically do not require a permit unless they discharge directly to a fish-bearing stream. If discharging to a watercourse, DFO notification and possibly an Environmental Management Act authorization may be required.

Three-Cell Treatment Pond

A series of three connected ponds, each performing a different treatment function. The first cell settles solids, the second supports biological breakdown, and the third provides final polishing with aquatic plants. The result is progressively cleaner water across the system.

Best for

  • Larger properties and farmsteads
  • Farm runoff and barnyard drainage
  • Stormwater management
  • Creating productive aquatic habitat

How it works

  • Cell 1 (Settling): Deep cell where solids settle out. Anaerobic digestion at the bottom.
  • Cell 2 (Biological): Shallower, aerated cell where aerobic bacteria break down dissolved organics.
  • Cell 3 (Polishing): Shallow, densely planted cell. Aquatic plants absorb remaining nutrients. Final filtration.

Sizing

  • Total volume (m³) = daily flow (L/day) / 200 (provides 5-day retention)
  • Divide total volume equally into 3 cells
  • Cell 1 depth: 2-3 m
  • Cell 3 depth: 0.5-1 m

Plants (Cell 3)

  • Yellow flag iris (Iris pseudacorus)
  • Bulrush and rushes
  • Duckweed (Lemna spp.)

Maintenance

Remove accumulated sludge from Cell 1 every 3-5 years. Thin plants in Cell 3 annually. Monitor inlet and outlet structures.

BC Regulatory Note: Treatment ponds handling sewage require engineered design and a sewage disposal permit. Ponds treating only stormwater or surface runoff generally do not need permits unless they impound a stream or exceed dam safety thresholds (wall >1.8 m or volume >30,000 m³).

Constructed Soil Biofilter Bed

A layered filter bed consisting of gravel, sand, topsoil, and compost that physically and biologically treats water as it percolates through. Simple to construct, effective for pre-treatment, and suitable for a wide range of water sources.

Best for

  • Pre-treatment before cistern or tank storage
  • Cistern inlet filtration
  • Pond water quality improvement
  • Roof runoff polishing

How it works

Water is applied to the surface and percolates downward through four distinct layers. Each layer performs a different function: compost hosts biology that breaks down organics, topsoil provides fine filtration, sand removes smaller particulates, and gravel provides drainage and support. Treated water is collected via a perforated drain at the base.

Sizing

  • 0.5 m² per 100 L/day
  • Minimum bed depth: 600 mm

Layer specification (top to bottom)

  • 100 mm compost (finished, screened)
  • 150 mm topsoil (loam, weed-free)
  • 200 mm washed sand
  • 150 mm drainage gravel (20-40 mm washed)

Maintenance

Replace compost layer every 2-3 years. Clear surface debris. Monitor flow rate — reduced flow indicates the sand layer needs raking or replacing.

BC Regulatory Note: Biofilter beds treating surface water or rainwater typically do not require permits. If treating greywater or any waste stream, check with your local health authority.

Size your system

Enter your details and the calculator will estimate the system size, materials, and cost range for your chosen treatment type.

Auto-calculated: greywater = 80 L/person, full household = 200 L/person

Recommended plants (BC native/appropriate)

    Materials list

      BC regulatory pathway

      BC regulatory framework

      Greywater reuse

      Greywater systems (sinks, showers, laundry) are regulated at the regional health authority level. Some areas require permits, others only notification. Systems must not create standing water, ponding, or runoff to neighbouring properties.

      BC Sewerage System Regulation / Local Health Authority

      Septic effluent treatment

      Any system treating sewage or septic effluent requires a sewage disposal permit. Constructed wetlands polishing septic output must be designed by an Authorized Person under the Sewerage System Regulation.

      BC Sewerage System Regulation

      Stream discharge

      Discharging treated water to any watercourse may require authorization under the Environmental Management Act. Water quality must meet receiving environment standards. Monitoring may be required.

      Environmental Management Act

      Fish-bearing streams

      Any works within 30 m of a fish-bearing stream require a Riparian Areas Assessment. DFO notification is required if there is any potential to impact fish habitat. Penalties for non-compliance are severe.

      Federal Fisheries Act / Riparian Areas Protection Act

      Agricultural land

      Properties within the Agricultural Land Reserve may have additional flexibility for farm-related water treatment systems (manure management, field runoff). The Agricultural Land Commission recognizes water management as a farm use.

      Agricultural Land Commission Act

      Surface water / stormwater

      Bioswales and biofilter beds treating surface stormwater on your own property generally do not require permits. However, if the system impounds water (dam safety thresholds) or discharges to a stream, additional authorization may apply.

      Water Sustainability Act / Dam Safety Regulation

      When in doubt, call FrontCounter BC: 1-877-855-3222
      Campbell River office: 250-286-9300 — 1336 Island Highway, Campbell River, BC

      Ready to clean your water naturally?

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